This requires ignoring that Barry has been entering superspeed
at superspeed for the entire series. To list just a couple of very early examples, he entered superspeed in response to a bullet being fired from behind him, catching it before it enters his neck (S1E12), and in response to a lightning bolt coming down from the sky before it could hit the car he was in (S1E15)
The idea that he can't think at superspeed as you claim here:
Is obviously false as they wouldn't be able to run through the city without running into stuff every single time if they didn't have enhanced perception. But for specific proof, Barry located a specific missing file by speedreading through cabinets in S1E5, a search that would specifically have taken days if done normally. The S1E15 example also works here as we're explicitly shown his POV of the lightning moving in slow motion, showing that yes he does perceive the world as slow while going fast. Or even just
S1E1, which also has him perceive the world as slow before he even knows he has superspeed.
Once again, those examples are from Season 1 where Barry was much slower and far less in control of his powers than he would later be.
Flash is a show that loves to have him inflicted by PIS and introduce things he's always done as if they were new (see also their absurd insistence that he was in the low machs for years), just because it says stupid things doesn't make the showings disappear, and as I've just established Barry could do that stuff from the start.
Being on a new planet is completely irrelevant as Ego has no effect that affects teleportation, and Charmed teleportation can go across planes of existence so it's not like it only works on Earth.
In episode 98, Phoebe is in Egypt and Piper uses a spell to determine where she is (using a talisman that ends up falling on a globe) and only learns that she's in Egypt. As soon as she knows this,
Paige proceeds to teleport the two of them there. This handily beats out both the range requirement
and the imprecise location, since Egypt is much further away from San Francisco than a few miles, and the possible location of your team ("on the other side of the palace") is much smaller than "She's in Egypt". Paige had of course never visited that particular Egyptian tomb, so it shows her teleporting places she hasn't been too.
This is an argument that doesn't even make sense with your own actions. If it was true, you would just argue that Sylar can't counter the timestop at all because he starts without line of sight on your team and is also miles away.
The very fact that you acknowledge that he can break the timestop at the start of your strategy shows that you believe he can do it without seeing Legion and from a distance.
Good thing I explained how Charlie finds her? Quake can sense vibrations, it's part of Daisy's Terrigenesis upgrade.
While the Source was difficult to destroy by Charmed standards, it wasn't 'durable' in the sense that it could ignore attacks as far as I can recall. It's as vulnerable to getting smacked around by telekinesis to interrupt big moves as anyone else.